Manufacture of chipboard products, for instance, makes use of dispersal of material in the preparation of a blank, whereby a mix of chips and binder is fed, e.g., onto a conveyor band or into a mould in order to form a blank. The blank is cut and transferred to a platen press, where the blank containing chips and binder is pressed into a chipboard. When using a platen press for the manufacture of a chipboard product, planar products only can be fabricated without resorting to a mould. The gap of a platen press is capable of producing only one sheet product at a time. The manufacture of nonplanar products with nonrectangular cross-sections necessitates the use of moulds, which contributes to higher costs.
An example of a nonplanar product is a wedge-shaped roofing shingle. The traditional art of making shingles is based on manual cleavage of wood using an axe. This procedure is laborious and, moreover, the fire safety of wooden shingles is substandard. Wedge-shaped roofing shingles have been manufactured by moulding from a cement-glued chipboard offering an improved fire safety over that of wooden shingles. The moulds used in the so-called "wet" method are costly. Due to the increased product weight, weight-reducing aggregates are necessary resulting in a worsened product strength. Furthermore, the "wet" method causes wastewater problems.
A roofing shingle or similar wedge-shaped product can be produced from a thick blank by sawing the blank into wedge-shaped forms. This results in high material losses and appreciable equipment and saw blade costs. Furthermore, a roofing shingle produced by sawing is inferior by appearance and quality.